The gradual “solarisation” of Australia’s electricity grid and – and ultimately the whole economy – has gathered pace in the past week, with three new big solar farms totalling more than 370MW joining the grid and starting to deliver output into the National Electricity Market.

Each of the new solar projects – Bungala in South Australia, Bannerton in Victoria and Colleambally in NSW – ranks as the biggest solar projects in their respective states, indicating that the scale of solar projects is also growing. Meanwhile, in Queensland, another handful of big solar projects are nearly ready.

In South Australia, the 110MW second stage of the Bungala solar farm near Port Augusta has connected to the grid, and when it starts producing will add to the 110MW first stage and become the country’s biggest solar plant at 220MW.

Bungala is owned by Italian energy giant Enel Green Power, along with the Dutch Infrastructure Fund, and has signed a power purchase agreement with Origin Energy.

Origin Energy’s head of operations Greg Jarvis told RenewEconomy earlier this week that the cost of solar, and wind, was now cheaper than the marginal cost of generation at existing coal plants, confirming that the future would be based around renewables and storage such as batteries and pumped hydro.

This assessment has been confirmed by many at the All Energy conference in Melbourne, all pointing to solar costs in the mid $40s/MWh, allowing retailers, and some customers directly, to put together off-take packages that slash the cost of electricity for large consumers.

In NSW, the Colleambally solar farm, owned by Neoen and located near Griffith,, has started generating to the grid, and when complete will, at 150MW, be the biggest solar farm in the state.

Neoen, which also owns the Hornsdale Power Reserve, also known as the Tesla big battery, as well as solar farms in Griffith, Parkes and Dubbo, and other projects in the pipeline such as the Numurkah solar farm in Victoria, started construction on Colleambally little more than a year after proposing the facility, highlighting the speed with which solar farms can be delivered.

The Coleambally solar farm signed a 12-year PPA with EnergyAustralia last year – for 70 per cent of the output – although the price details of the contract have not been released.

In Victoria, that states’s biggest solar farm to date, the 110MW Bannerton solar farm, has also started generating. It will overtake the Ganawarra solar farm as the biggest project to date, although it will likely be overtaken by other bigger solar projects, such as the 112MW Karadoc solar farm also under construction.

And in Queensland, the Daydream solar farm and the neighbouring Hayman solar farm – both among a handful of project located around the old Collinsville power station, have begun the final preparations before connecting to the grid.

Queensland, though, is undoubtedly the leader in new large scale solar developments, with 13 large scale solar projects already connected to the grid, and another 16 under construction, and several dozen in the pipeline and queueing for position.

Giles Parkinson is founder and editor of Renew Economy, and is also the founder of One Step Off The Grid and founder/editor of The Driven. Giles has been a journalist for 35 years and is a former business and deputy editor of the Australian Financial Review.

Giles Parkinson is founder and editor of Renew Economy, and is also the founder of One Step Off The Grid and founder/editor of The Driven. Giles has been a journalist for 35 years and is a former business and deputy editor of the Australian Financial Review.